The effects of ionising radiation on copy number variation in the mouse germline. (360G-Wellcome-091106_Z_10_Z)

The proposed research aims to evaluate, for the first time, the genome-wide effects of irradiation on the incidence of copy number variation (CNV) and other mutations in the first-generation offspring of irradiated male mice. Using microarray-based comparative genomic hybridisation, we will analyse DNA samples taken from the offspring of control and irradiated (3 Gy of acute X-rays) parents. The structure of de novo CNV rearrangements verified by qPCR will further be interrogated by sequencing o f long-range PCR products encompassing the breakpoints of the rearrangements. This work will allow us to establish the relative contribution of different mechanisms for spontaneous and radiation-induced rearrangements. Further characterisation of the full spectrum of radiation-induced mutations will be performed by whole-genome sequencing of a small subset of the offspring of irradiated parents. To investigate the effects of de novo genomic rearrangements on the expression of genes, RNA samples will be extracted from the offspring and hybridised to expression arrays. It is expected that the results of this study will provide fundamental quantitative information on the effects of exposure to ionising radiation on mutation induction in mice and will be important in improving the accuracy of the estimates of genetic hazards of ionising radiation for humans.